Impacts of Heat Stress and How to Manage It

When waves of heat rise from the ground to blur the air above and the heat index spikes to triple digits, outdoor workers aren’t just uncomfortable, they face serious risk. As our commitment to safety at ODG is paramount, we’re especially attuned in the summer months to the dangers of heat stress, which can cause illnesses such as heat stroke, heat exhaustion, heat cramps, rashes, syncope (fainting), and rhabdomyolysis (muscle destruction and related kidney dysfunction).

Even when outdoor temperatures are not yet extreme, added heat from machinery can elevate heat to dangerous levels. Protective personal equipment (PPE) also increases the risk of heat stress, as it traps heat and moisture and can increase the physical effort needed to perform work. Heat can cause indirect injuries by resulting in sweaty hands, foggy safety glasses, and dizziness.

We train teams not only to understand how heat stress affects health and safety, but also to prevent it, and, if necessary, treat it. A division of the CDC, the National Institute for Occupational Safety and Health (NIOSH) provides excellent resources for prevention and response, including training tools, apps, signage, and specific guidelines for acclimatization schedules, rest breaks and other interventions.

How to Prevent Heat Stress

  • Control: Reduce heat sources and exposure through engineered controls, such as fans, heat-absorbing or reflective equipment. Limit risk through scheduling and work practices, considering length of shifts, recovery time, number of workers, and optimized efficiency.
  • Training: Ensure that training is clearly communicated in all necessary languages. Train workers and supervisors on recognition, prevention measures such as acclimatization, and treatment.
  • Acclimatization: Gradual increased exposure to hot environments is key to reducing the risks of heat stress. Acclimatization should span 7 to 14 days, slowly increasing workers’ time in hot conditions in 20 percent increments. NIOSH offers specific timetables for acclimatization. Note that those who aren’t physically fit will take longer to acclimatize. Taking breaks in air-conditioning does not affect the process.
  • Hydration: Employers should provide plenty of cool, potable water near jobsites and encourage workers to hydrate adequately. When working in the heat, drinking 24-32 ounces per hour is recommended.
  • Rest: Shorten work sessions and lengthen rest periods when temperature and humidity are high, if there is no air movement, if PPE is worn, and for heavier, more intense work.

Symptoms and Treatment of Heat Stroke and Heat Exhaustion

Heat stroke and heat exhaustion are the most common illnesses related to heat stress, so it’s important to recognize their symptoms and know how to treat those who exhibit them.

Heat stroke robs the body of its natural ability to regulate its temperature. Temperature rises quickly, sweating stops, and the body cannot cool down. Body temperature can rise to 106°F and higher in just 10 to 15 minutes. The condition is fatal if treatment is delayed.

Symptoms of heat stroke (Source: NIOSH)

  • Confusion, altered mental status, slurred speech
  • Loss of consciousness
  • Hot, dry skin or profuse sweating
  • Seizures
  • Very high body temperature

Treatment of heat stroke (Source: NIOSH)

  • Call 911 for emergency medical care.
  • Stay with the worker until emergency medical services arrive.
  • Move the worker to a shaded, cool area and remove outer clothing.
  • Cool the worker quickly, using the following methods:
    • With a cold water or ice bath, if possible
    • Wet the skin
    • Place cold wet cloth on the skin
    • Soak clothing with cool water
    • Circulate the air around the worker to speed cooling
    • Place cold wet cloth or ice on the head, neck, armpits, and groin, or soak the clothing with cool water.

Heat exhaustion is the body’s response to the loss of water and salt through excessive sweating. Elderly people and those with high blood pressure are more susceptible to it, but anyone can experience it.

Symptoms of heat exhaustion (Source: NIOSH)

  • Headache
  • Nausea
  • Dizziness
  • Weakness
  • Irritability
  • Thirst
  • Heavy sweating
  • Elevated body temperature
  • Decreased urine output

Treatment of heat exhaustion (Source: NIOSH)

  • Take worker to a clinic or emergency room for medical evaluation and treatment.
  • Call 911 if medical care is unavailable.
  • Have someone stay with the worker until help arrives.
  • Remove the worker from the hot area and give liquids to drink.
  • Remove unnecessary clothing, including shoes and socks.
  • Cool the worker with cold compresses or have the worker wash their head, face, and neck with cold water.
  • Encourage frequent sips of cool water.

Knowing how to protect workers from heat stress is a crucial aspect of workplace safety in the summer. Help everyone on your crews know what to look for and how to respond, and enjoy a safe summer!